Teletherapy device



Filed July A14, 195e lfilsl S L0 a WITNESSES R. L. GUENTNER ETAL res'TELETHERAPY DEVICE 2- Sheets-Sheet 1 Fig.|.

no \N INVENTORS Robert L. Guentner 8 Edwo rd F. Moran ATTORNEY 3,073,960TELETHERAPY DEVICE 2 Sheets-Sheet 2 Jan. 15, 1963 R. L. GUENTNER ETALFiled July 14, 1958 w.. ON-

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M MM 3,073,3*60 TELETHERAPY DEVHCE Robert L. Guenther, Catonsvilie, andEdward F. `Mrau, Baltimore, Md., assignors to Westinghouse ElectricCorporation, East Pittsburgh, Pa., a corporation of Pennsylvania FiledJuly 14, 1958, Ser. No. 748,35@ 6 Slainis. (Qi. Z50-10S) This inventionrelates to shielded teletherapy devices for holding a source ofradioactive material and directing a beam of radiant energy therefromfor the treatment of disease; and more particularly to such sourceholder devices as provide for regulation in the size and pattern of theradiation beam to suit different areas of exposure of patientsundergoing treatment.

Certain prior art source holder devices of the above general type haveemployed adjustable field collimators in the form of heavy interleavedsliding blocks for shielding material which may be operated like adiaphragm to control the extent of opening of a beam emergence aperture.Such collimators are inherently expensive and limited as to beam shape.Another prior art source holder device employs various-sizedheavy-walled hollow beam collimator members, or cones, which are handledmanually for substitute mounting on the device. This particularcone-substitution arrangement, while enabling selection of both beamsize and pattern, involves considerable work and effort on the part ofoperating personnel since each of the cones which must be handled mayweigh as much as fifty pounds and an exchange of cones to a differentsize is usually necessary before each treatment.

in View of the foregoing remarks, it becomes a prime object of thepresent invention to provide an improved radioactive source materialholder of the type which enables regulation of the size and pattern ofthe radiation beam in a simple and facile manner.

Another object or" the present invention resides in the provision of animproved radioactive source material holder which carries a plurality ofcones of radiation absorbing material arranged to be rendered effectiveselectively for regulation of the size and/or pattern of the radiationbeam.

Another object of the present invention resides in the provision of aradioactive source material holder having a plurality of radiallydisposed cones arranged for rotary movement in unison about a centralsource station to bring selected ones of such cones into registry with abeam emergence aperture originating at such source station.

Another object of the present invention resides in the provision of aradioactive source material holder having means defining a centralguideway along which the source material may be moved from anon-operative position at a repose station to an operative position atthe central source station within the cone assemblage.

Another object of the present invention resides in the provision of aradioactive source material holder having a radial cone assemblageprovided with manually-operable means to effect rotary movement of suchassemblage for accurate orientation of the radiation beam emergenceaperture and maintenance of a selected position.

Other objects and advantages of the invention will become apparent fromthe following detailed description of such invention when taken inconnection with the accompanying drawing, in which:

FIGURE l is a side sectional view, several components being in outline,of the source material holder embodying the invention;

FIG. 2 is a front View, substantially in outline and partly in section,of the source material holder taken along the line H-II in FIG. l, withportions cut away to expose certain components;

FIG. 3 is a fragmentary sectional View, taken along the line Ill-lll inFIG. 2, showing details of a friction assemblage employed in the sourcematerial holder;

FIG. 4 is a fragmentary sectional view, taken along the line IV-lV inFIG. 2, showing details of a detent structure employed in the sourcematerial holder; and

FIG. 5 is a fragmentary sectional view, taken along the line V-V in FIG.2, showing details of a roller structure employed in the source materialholder.

The source holder embodying the invention is primarily, though notnecessarily, intended for employment with a cobalt-60 source, and toprovide adequate shielding with minimum bulk includes a generallyspherically shaped hollow metal container 1d filled with lead 11 inwhich is centrally located a source capsule 12 when in a non-operativeposition at a repose station. One end of the container 1li is blunt andenclosed by a substantially disc-shaped front Wall 14 to which isattached a cylinder member 16 extending inwardly of container 1dcentrally of wall 14. An end member 18, attached to the innermost end ofthe cylinder member 16, is provided With a fluid pressure port 2d toenable ingress and egress of fluid under pressure to and from a pressurechamber 21 via a conduit 24 and external fitting 26 for actuation of thesource capsule 12 in manner as will be set forth in detail hereinafter.

A hollow cylinder member Z8 is rotatably mounted in cylinder member 16to act as a cylindrical guideway for directing movement of the sourcecapsule 12 from its repose position in which -it is shown in FIG. 1 toan operative position hereinafter dened, and to define the hub of anovel radiation emergence portion 3i) of the source holder.

The radiation emergence portion 30 includes a substantially cylindricalmetal shell 32 filled with lead 3d, the central portion of shell 32being defined by .an extension of the cylindrical member 28 which isattached to such shell by means such as welds (not shown). An end of theshell 32 adjacent to front wall 14 of container 1f) is defined by anannular end wall 3d and bearing race support member 33 encircling member28, each component being attached suitably one with the other to providea fluid tight container adapted for holding the lead 34 when introducedinitially in its molten state. The periphery of the shell 32 is definedby an elongated ring member 4t), and the outer end of such shell isdefined by a portion including an annular tiange 42 attached at itsouter periphery to ring member 40, an integral rustro-conical portion 44and annular end'wall 46 attached at its inner periphery to cylindermember 28.

The source capsule 12 is carried in an end portion 47 of an elongatedpiston member 48, such end being of steel, for example, and theremainder being filled with lead 50. End portion i7 of piston 58 isprovided with a cylindrical socket 52 adapted for registry, in adisplaced position of piston 48, with an aperture 54 defined by a sleevemember 56 associated with portion 3d and extending radially outward fromcorresponding apertures in cylinder member 28 at its inner end and inring member 40 at its outer end. Registry of socket 52 with sleevemember 56 enables the source capsule 12 to be inserted and removed intoand from such socket via aperture 54 either by way of the interior ofone of a plurality of removable lead cones SS, to be describedsubsequently, or directly by way of the sleeve member 56 with therespective cone 58 removed. A lead plug 60, removably secured by a setscrew 61, normally fills the aperture 54 subsequent to insertion of thesource capsule 12 into socket 52. An emergence port 6d opens from thesocket 52. radially of piston member 48 for registry with a taperedradiation emergence aperture 66 formed by a hollow member 67 extendingradially from cylinder member 28 and sleeve member `4t) for emergence ofradiation from capsule 12 to the exterior of the source holder when thepiston member 48 is nid pressure actuated to attain such registry.

.A return spring assemblage 69 is arranged to return the pistonassemblage 48 to the repose position in which it is shown in FIG. 1 withsource capsule completely shielded. In such repose position, a source ofvisible light in the form of a bulb 70 is brought into registry with theemergence aperture 66 to provide for focusing such aperture by visiblelight with the target area of a patient to undergo teletherapy.

To enable the emergence portion Si) and piston member 48 to be turnedabout the axis of such piston member for selective orientation of theradiation emergence aperture 66 while at the same time relieving thehollow cylinder member 28 of the load of such portion and providing arelatively frictionless rotary connection, a tapered roller bearingassemblage 71 is interposed radialwise between bearing race supportmember 38 and a portion of wall 14 of container 1i?, and a ball typethrust bearing assemblage 72 extends radialwise in interposition betweenwall 14 andsuch portion 3l). An outer raceway 73 of assemblage 72. isremovably secured by screws 74 to wall 14,

Vand the inner raceway 75 of assemblage 72 is attached to a plurality'of bolts 76 which extend through portion 3), including an annular endmember 77 attached to end wall 46 of such portion By means of nuts '78,the portion 3i? is removably attached to container 16 through the mediumof the bolts 76 and thrust bearing assemblage 72.

To enable accurate and facile rotary movement of the beam emergenceportion 36, relative to container 10, a handwheel 82 is provided whichis rotatably supported on the outer periphery of end member 77 throughthe medium of `roilers S3 and is connected to container 1t? through agear train. The gear train includes a large ring gear 84 attached tohandwhecl 82, an engaging small gear S attached to one end of arotatable shaft 86 journaled in end member 77 and extending through lead34 and end wall 36, a gear 87 attached to the opposite end of shaft 86,and a gear 88 attached to the front wall 14 of container 10. An idlergear, not shown, may be suitably arranged in such gear train where it isdesired to change the directionality relationship between rotarymovement of shell 32 and that of the handwheel 82. apparent by referenceto lFIG. 2, that turning movement of shaft 86 around its own axisthrough the medium of handwheel 82 and gears 84, 85 will cause gear 87to roll around gear 88 and carry such shaft 86 and shell 32 with it,thereby turning the emergence aperture 66 about the axis of the pistonmember 48 which will also be turned correspondingly during the turningof cylindrical member 2S in which it is disposed.

To assure that the emergence portion 3i) may not accidentally be movedfrom a selected rotary position relative to container 1t), a frictionassemblage 92, FIG. 3, is provided. VThe friction assemblage 92 includesa shoe member 94 urged by a spring 95 into sliding frictional engagementwith the end face of iront wall 14 of the container 10. Shoe member 94and the spring 9S are disposed within a bore 96 extending in anaxialwise direction through the metal shell 32 and the lead 34 withwhich it is lled. A removable spring seat member 97 extends into thebore 96 for compressive engagement with the spring 95, and a removablesecuring member 9S is attached to spring seat 97 and mounted on theouter face of end wall 46 of the shell 32 for access to the bore 96 andthe components disposed therein.

The spring assemblage 69 extends into the end of a hollow extendedportion i) of piston member 48 and into contact at its one end with aninterior wall 101 ot the piston member. The opposite end of the springassemblage is in thrust engagement with an end wall 1134 It will be of acylindrical spring container 106 which is attached at a flanged end 167to the end member 77. A cover 108, attached at 169 to spring container106, encases same and covers a substantial front portion of thehandwheel 82 primarily to enhance the appearance of the source holder.

A tab 110, attached to the end of the hollow extended portion of pistonmember 48, extends radially outward therefrom through a longitudinalslot 111 in spring container 196. During rotary movement of theemergence portion 30 by manipulation of the handwheel 82 for orientationof the radiation emergence aperture, the spring container 106 attachedto end member 77 will turn in unison with the shell 32, and throughcontact of a side wall of the slot 111 with the tab 11i), turning of thepiston member 48 in unison with portion 30 for proper registry ofemergence ports 64 and 66 in unison with portion 3ft will be assured. Inaddition, an elongated slot 114 in registry with slot 111 is formed inthe cover 10S for accommodation of the tab 11G during iluid pressureactuation of the piston member 48 to enable the tab 110 to projectoutwardly therefrom to serve as indication that the source capsule 12 isin its operative position at the radiation emergen-ce aperture 66. Uponreturn of the piston member 48 to its repose position in which it isshown in FIG. 1, the tab 116' will become disposed within cover 108 toindicate that the source capsule 12 is disposed in its fullyshieldedinoperative position.

The spring assemblage 69, in addition to its normal piston-returningfunction, represents a fail-safe arrangement to assure return of thepiston member 48 automatically, should pressure ot iluid in the source(not shown) supplying chamber 21 become depleted accidentally at a timewhen the piston member 48 was positioned for registry of source capsule12 with the emergence aperture 66.

In accord with a prime feature of the invention, an emergence portion 30is provided with a mounting ring 116 encircling shell 32 and mounted forrotary movement on the periphery of ring member 4G through the medium ofa plurality of circumferentially spaced-apart roller assemblages 118,FIGS. 2 and 5, each of which includes, FIG. 5, a pair of rollers 120rotatably mounted on a shaft 121 disposed in a bore 124 and locked by aset screw 125. Tracks in the form of grooves 126 are formed in theperiphery of ring member 4t) to guide the rollers 120 and retain themounting ring 116 on such member.

Each of the lead cones 58 or beam collimator members has a beamemergence aperture 130, FIG. 2, extending axially therethrough, theseveral apertures of the various cones being of diterent sizes and/ orshapes to delne radiation beams suitable to the Various treatment areas.Each cone SS includes preferably a base portion 132 of standard outsidedimensions and an extension portion 134 of shape and size respective tothe particular aperture 130. The base 132 of each cone 58 includes asocket portion which tits in accommodating receptacles atcircumferentially spaced-apart intervals around the mounting ring 116and 1s locked in place by such as a split locking ring 136, FIGS. l and2, itted in a groove 138 in base 132, FIG. 2, and secured to ring 116 byscrews 140, FIG. 2. The locking ring 136 is shown in FIG. 2 with respectto only one of the cones 58, however, it may be l presumed that each ofthe cones 58 will be similarly secured to the mounting ring 116. Itshould be pointed out that the number of cones 58 carried by themounting ring 116 is suiciently great to satisfy the larger sizedtreatment areas encountered during employment of the source holder andthe mounting of these cones may be considered to be permanent.

According to other important features of the invention, the mountingring 116 is provided with a heavily-shielded integrally-formed coneportion 142 which is lled with lead 144 and is adapted to receive arelatively lightweight insert member 146 of radiation absorbingmaterial, such as lead or bronze, having an aperture 147 to define, theradiation bea-m where treatment areas reside in and around a patientsthroat, or neck, for example, and it is desirable to have available arelatively great number of smaller beam sizes and shapes. For thisreason, a tapered latch member 148 is provided which is biased by aspring 150 into locking engagement with an annular shoulder 151 at theedge of a tapered groove 152 formed in the outer periphery of each ofthe insert members to be employed in cone portion 142. During insertionof an insert member 146, the latch member 148 will be displaced by theleading portion of member 146 until registry with groove 152 isattained, whereupon locking becomes automatic. To effect retraction oflatch member 148 for removal of the insert member 146, a pull may beexerted on a circular handle 154 which is attached to such latch member14S via a rod 156. Since the shielding is done primarily by thelead-filled portion 142, the insert members 146 may be of relativelylightweight construction to reduce the burden involved in frequentexchange during respective employment of the device. The

lead-filled portion 142, is tapered or conical-shaped at its projectingend to enable it to easily be extended between such portions of apa-tients anatomy as the head and shoulders in close proximity totreatment areas on the throat or neck with assurance that other areaswill be exposed to a minimum amount of stray radia-tion.

Rotation of the cone assemblage to bring selected ones of the cones 5Sor portion 142 into registry with the beam emergence aperture 66 is donemanually by grasping, for example, one or the other of such cones andexerting a turning effort thereagainst. Detent means 160, FIG. 4, isemployed to deline and yieldably lock the cone assemblage in positionswith respect to ring member 40 corresponding to the registered positionof selected ones of the cones 58, including portion 142 of mounting ring116. Such detent means 160 includes a rolle-r assemblage 161 mountedequidistant opposite ends of a rotatable shaft 162 which is containedwith radial clearance in a cylindrical opening 163 in mounting ring 116.Slotted retainer elements 164, locked by set screws 165 accommodatereduced end portions 166 of the shaft 162 to permit turning of shaft 162while serving to guide transverse movement of such shaft 16d and rollerassemblage 161 and while cooperating with annular shoulders 167 on suchshaft to prevent its escape from the opening 163. The roller assemblage161 is urged in the direction of the outer surface of ring member 40 tobe in constant contact therewith, by a pair of compression springs 170disposed in the mounting ring 116 and acting on the shaft 162. Aplurality of circumferentially spaced-apart recesses 172, one of whichis shown in FIG. 4, are formed in the outer periphery of ring member 40for cooperation, one at a time, with the roller assemblage 161 which isurged thereinto when either a cone 58 or the portion 142 is brought intoregistry with the beam emergence aperture 66. Each recess 172 is shapedto cooperate with the roller assemblage 161 for accurate delinition andyieldable retention of the selected cone in its operative position inalignment with the beam emergence aperture 66, while permitting suchroller assemblage to ride up and out of such recess for enabling rotarymovement of the cone assemblage when making cone selections.

Additional refinements of the source holder include the provision of acover 181i which is carried by the mounting ring assembla-ge to rotatetherewith during orientation of the beam emergence aperture 66 andenclose from view the inactive ones of the cones 58 or portion 142 asthe case may be. To enable projection of portion 142, in particular, andselected ones of the cones 58, in general, the cover 180 is reduced inits radialwise dimension and open peripherally at the beam emergencestation. A pointer 181, attached to the container 10, extends in frontof the cover 180 to cooperate with indicating marks, not shown, toindicate the rotary position of the emergence aperture 66 with respectto such container.

Since numerous changes may be made in the abovedescribed construction,and different embodiments of the invention may be made without departingfrom the spirit and scope thereof, it is intended that all mattercontained in the foregoing description or shown in the accompanyingdrawing shall be interpreted as illustrative and not in a limitingsense.

We claim as our invention:

l. A radioactive source holder comprising a rotatable shielded meanshaving a radioactive-source-accommodating cavity for containing a sourcecapsule and a radiallyextending radiation emergence aperture forregistry with said cavity, and a plurality of various sized and shapedcollimator members encircling said shielded means and rotatablethereabout for selective radially-aligned registry with theradially-outermost end of said emergence aperture.

2. In a radioactive source holder, the combination of a rotatablegenerally cylindrical shielded member having a central radioactivesource accommodating opening and radiation emergence aperture extendingradially outward therefrom to the exterior of such member, and aplurality of circumferentially arranged collimator members mounted onsaid shielded member for movement circumferentially therearound toattain selected radially-aligned registry with the radially-outermostend of said radiation emergence aperture.

3. A radioactive source holder comprising rst shielded means forcontaining a radioactive source capsule at a repose station and defininga shielded guideway along which said source capsule may be moved fromsuch repose station, second shielded means defining an opening inregistry with said guideway for receiving the radioactive source capsuleand having a radiation emergence aperture extending radially outwardfrom said opening, said second shielded means being mounted on saidfirst shielded means for rotary movement about the axis of said openingto enable selective positioning of said radiation emergence aperture atdifferent radial positions, and an assemblage of circumferentiallyarranged collimator members mounted in encirclement of said secondshielded means and movable relative thereto for selectiveradiallyaligned registry with said radiation emergence aperture.

4. A radioactive source holder comprising iirst shielded means forcon-taining a radioactive source capsule yat a repose station anddelining -a shielded guideway along which said source capsule may bemoved from such repose sta-tion, second shielded means defining anopening in registry with said guideway for receiving the radioactivesource capsule and having a radiation emergence Iaperture extendingradially outward from said opening, said second shielded means bein-gmounted on said rst shielded means for rotary movement about the axis ofsaid opening to enable selective positioning of said radiation emergenceaperture at different radial positions, an assemblage ofcircumferentially arranged collimator members mounted in encirclement ofsaid second shielded means and movable therearound for selectiveradially-aligned registry with said radiation emergence aperture, anddetent means for defining stop positions of said assemblage coincidentto attainment of registered positions of said collimator members withsaid radiation emergence aperture.

5. A Aradioactive source holder comprising first shielded means forcontaining a radioactive source capsule at a repose station and defininga shielded guideway along which said source capsule may -be moved fromsuch 'rep-ose station, second shielded means `defining an opening inregistry with said guideway for receiving the radio- `active sourcecapsule and having a radi-ation emergence aperture extending radiallyoutward from said opening, said second shielded means being mounted onsaid irst shielded means fo-r rotary movement labout the axis of saidopening to enable selective positioning of said radiation emergenceaperture |at different radial positions, manually operable means foreifecting said rotary movecollimaltor members mounted in encirelement ofsaid sec` ond shielded means :and movable relative thereto therearoundfor selective radially-aligned registry with said radiation emergenceaperture.

6. In a radioactive source holder, the combination of a rotatablegenerally cylindrical shielded member having a icentnal radioactivesource accommodating opening and radiation emergence aperture extendingradially out- Ward therefrom yto the exterior of such member, a circularcolli-mater assemblage mounted on said shielded member for movementcireumferentially therearcund, said eollimator Iassemblage including aplurality of circnrnferentially arranged lead icones xed thereto forselective radially-aligned registry with said radiation emergenceaperture to define different radiation beams emerging from said holder,and lat least one shielded socket interposed circumferential-wisebetween said cones for accommodating a removable lead insert member to Sdeiine a beam size smaller than those provided -by said cones.

References Cited in the le of this patent UNITE-D STATES PATENTS2,469,206 Rich May 3, 1949 2,487,222 Contant Nov. 8, 1949 2,523,067Sherry Sept. 19, 1950 2,670,443 Pennock et al. Feb. 23, 1954 2,687,477Pfaff Aug. 24, 1954 2,706,789 Hughes Apr. 19, 1955 2,750,517 Baum June12, 1956 2,772,361 Hiestand Nov. 27, 1956 2,777,356 Stegeman Jan. 15,1957 2,849,621 Clark Aug. 26, 1958 2,872,587 Stein Feb. 3, 19592,978,587 Forro Apr. 4, 1961

1. A RADIOACTIVE SOURCE HOLDER COMPRISING A ROTATABLE SHIELDED MEANSHAVING A RADIOACTIVE-SOURCE-ACCOMMODATING CAVITY FOR CONTAINING A SOURCECAPSULE AND A RADIALLYEXTENDING RADIATION EMERGENCE APERTURE FORREGISTRY WITH SAID CAVITY, AND A PLURALITY OF VARIOUS SIZED AND SHAPEDCOLLIMATOR MEMBERS ENCIRCLING SAID SHIELDED MEANS AND ROTATABLETHEREABOUT FOR SELECTIVE RADIALLY-ALIGNED REGISTRY WITH THERADIALLY-OUTERMOST END OF SAID EMERGENCE APERTURE.